The paedophile paid £10,000 by police to infiltrate the depraved sex gang that groomed women and girls said he intends to sue the force.
The former convict said he agreed to spy on the ring if his identity was kept secret.
He said that was broken when he was made to testify in court.
He told the Sun: ‘The police signed an agreement with me from the start that they would never put me in this kind of position.
‘I should never have been dragged into that courtroom for people to see me.’
He says he now intends to discuss the matter with his solicitor.
His evidence helped convict 17 men and one woman of charges including rape, supplying drugs and inciting prostitution as part of a major secret operation in Newcastle.
Dubbed ‘Operation Shelter’ it uncovered older men preying on immature, vulnerable teens who were then plied with cocaine, alcohol, mephedrone and cannabis before being raped or persuaded into having sexual activity with the lure of further drugs.
The details of the group’s horrific crimes came to light in a series of cases at Newcastle Crown Court.
Over the course of four trials, 20 young women gave evidence about the crimes that happened between 2011 and 2014.
The victims were all females between 13 and 25.
Those gang’s members came from the Bangladeshi, Pakistani, Iraqi, Indian, Iranian and Turkish communities and were mostly British-born.
The wider inquiry, called Operation Sanctuary, has so far resulted in about 100 people convicted of a range of offences including drugs, modern-day slavery and firearms charges, with jail terms totalling more than 300 years.